package second.dp;

public class Solution37 {
    public int maxProfit(int[] prices) {
        int len = prices.length;
        int[][] dp = new int[len][4];
        dp[0][1] = -prices[0];
        for (int i = 1; i < len; i++) {
            dp[i][1] = Math.max(dp[i - 1][1], dp[i - 1][2] - prices[i]);
            dp[i][2] = Math.max(dp[i - 1][2], dp[i - 1][3]);
            dp[i][3] = dp[i - 1][1] + prices[i];
        }
        return Math.max(dp[len - 1][2], dp[len - 1][3]);
    }
}
